The present invention relates to an integrated circuit with a housing accommodating the integrated circuit. It being possible for the integrated circuit to be put optionally into one of a plurality of different operating modes by virtue of the selective provision of electrical connections between specific contact points constructed on the integrated circuit.
A unit of this type, which is referred to below in short as xe2x80x9cdevicexe2x80x9d, is, by way of example (but not exclusively), a memory device which is provided, by way of example (but once again not exclusively), for mounting on a single in-line memory module (SIMM).
A SIMM equipped with conventional memory devices is shown in FIG. 2. The memory devices are soldered onto a printed circuit board. Along one of its edges, the printed circuit board is provided with a multiplicity of contact elements situated next to one another, with the result that it can be plugged onto a further printed circuit board (not shown in the figure), more precisely into a printed circuit board connector provided on the same.
A known area of application for such SIMMs are personal computers, where the SIMMs are used as main memory modules.
As is known, the memory devices exist in a multiplicity of variants that differ not only in respect to the housing but also in respect to their organizational forms and operation modes.
The different organizational forms have an effect, in particular, on the size of the units in which the data that are to be stored in the respective memory device or are stored therein are to be input or are output. More precisely, the organizational form defines Inter alia how many bits or bytes an individual datum that is to be input or is output respectively has. Depending on this, the address to be applied to the memory device so that a specific memory area can be accessed may also vary.
The different operation modes have an effect, inter alia, on the driving of the respective memory module and the particular reaction of the memory module to the driving. Examples of different operation modes are the EDO (enhanced or extended data out) mode, FPM (fast page mode), different types of refresh cycles, etc.
The organizational form and the operation modes must be adapted to the respective external circuitry of the memory module (the controller which drives the circuitry or vice versa).
The various housings differ in respect to the number of terminal elements (e.g. pins) they have, in particular in respect to the number of terminal elements for address and data input and/or output. The number of terminal elements depending on the organizational form chosen, and in respect of the way in which they can be mounted on the printed circuit boards.
The housing of the memory devices shown in FIG. 2 is a so-called SOJ housing, which is very often used for memory devices and, for its part, is likewise manufactured once again in a variety of embodiments having different numbers of terminal elements.
The multiplicity of different housings and also the multiplicity of different organizational forms and operation modes of the integrated circuits require, as may be recognized, frequent changeovers (material and tool changes) during the fabrication of the memory devices and render efficient inventory management virtually impossible.
Therefore, a transition has been made to fabricating and using integrated circuits which, after they have been fabricated, can be configured more or less freely in respect to their organizational form and their operation modes, in other words can be used for a multiplicity of different (memory) devices.
By way of example, the configuration can be realized in this case by providing electrical connections selectively between specific contact points of those constructed on the integrated circuit. The electrical connections are wire connections (interconnections) which are provided within the housing and are fabricated by bonding, for example.
By virtue of such interconnections, which are preferably not implemented until the integrated circuit is accommodated in the housing, which is still adapted to the individual requirements, the integrated circuit can be put as desired into different operating modes by which the integrated circuit is respectively assigned a quite specific organizational form and quite specific operation modes.
The provision of one and the same integrated circuit as a starting product for a multiplicity of memory devices which operate in different ways and the configuration (individualization) thereof which takes place only at the end of the fabrication process simplify the fabrication of the different memory devices enormously.
Nevertheless, the fabrication of such memory devices is still a relatively laborious process because the configuration of the integrated circuit may require, depending on the construction of the housing in which the integrated circuit is to be accommodated, a different procedure and hence the use of different tools as well.
It is accordingly an object of the invention to provide an integrated circuit with a housing accommodating the integrated circuit that overcomes the above-mentioned disadvantages of the prior art devices of this general type, in which its fabrication can be standardized even further.
With the foregoing and other objects in view there is provided, in accordance with the invention, an electronic circuit, including: an integrated circuit having contact points and a plurality of different operating modes each definable by selecting various combinations of electrical connections between the contact points; and a housing having terminal elements for providing external contact and accommodating the integrated circuit, the contact points of the integrated circuit provided for defining an operating mode and configuration of the integrated circuit connected to the terminal elements.
Accordingly, it is provided that all the contact points of the integrated circuit which are provided for the operation and configuration of the integrated circuit are connected to terminal elements of the housing with which external contact can be made.
In other words, therefore, all the contact points of the integrated circuit are made externally accessible via corresponding terminal elements of the housing. As a result, on the one hand, the diversity of different housing variants can be reduced and, on the other hand, the configuration of integrated circuits that can be used universally can be removed entirely from the device fabrication process.
In this way, the device fabrication can be standardized considerably more extensively than has been the case heretofore.
The selection of which of the contact points of the integrated circuit are actually used (connected to external circuitry or interconnected), the contact points being lengthened outward in their entirety, can be made by the printed circuit board on which the relevant devices are to be mounted. This can be done, by way of example (but not exclusively), as follows: the printed circuit board can be brought onto contact (soldered) only with those terminal points of the device which are actually required for the planned use.
The configuration of the integrated circuit can also be defined by the printed circuit board. All that is necessary for this purpose is that the printed circuit board contain corresponding conductor tracks which connect the contact points of the integrated circuit which are to be connected in order to activate a specific operating mode, more precisely the terminal points of the housing which are connected to the contact points.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in an integrated circuit with a housing accommodating the integrated circuit, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
FIG. 1a is a perspective view of a SIMM equipped with memory devices configured according to the invention;
FIG. 1b is a partially cut away view of the memory device; and
FIG. 2 is a perspective view of the SIMM according to the prior art.